Elevator

local args = {...}

if #args < 2 then
  print("Need some parameters!")
  print()
  print("Usage:")
  print("elevator <direction> <floors>")
  print()
  print("direction is down or up")
  print("floors is a number")
  print("ie")
  print("elevator up 4")
  return
end

direction = args[1]

levels = tonumber(args[2])
if levels <= 0 or levels == nil then
  print("What the heck? I need a number to go up or down!")
  return
end
if turtle.getFuelLevel() < levels then
  print("I need some fuel, please give me fuel!")
  return
end

direction = string.lower(direction)
direction = string.sub(direction,1,1)

if direction == "d" or direction == "u" then
for i=1,levels do
  if direction == "d" then
    print("Going Down!")
    turtle.down()
  else
    print("Going Up!")
    print("Waiting for you to jump!")
    while not turtle.up() do
     print("Jump Now!")
    end
  end
end
else
  print("You can't follow instructions can you?")
end